一个小小的签到功能，到底用MySQL还是Redis？

last_checkin_time = time()checkin_count=1

last_checkin_time = time()checkin_count= checkin_count+1

last_checkin_time = time()checkin_count=1

//0点$today_0 = strtotime(date('y-m-d'));//昨天0点$yesterday_0 = $today_0-24*60*60;$last_checkin_time = $model->last_checkin_time;if(empty($last_checkin_time)){ //first checkin $model->last_checkin_time = time(); $model->checkin_count = 1;  }else{ if($today_0 < $last_checkin_time){  //checkin ed 当天已签到过  return json_encode(['code' => 0, 'msg' => '已签到成功']); } //昨天签到过 if($last_checkin_time < $today_0 && $last_checkin_time > $yesterday_0){  $model->last_checkin_time = time();  $model->checkin_count = $model->checkin_count + 1;  }else{  //昨天没签到过，重新计数  $model->last_checkin_time = time();  $model->checkin_count = 1; }}$rs = $model->save();

//每天一个key  $key = 'checkin_' . date('ymd');  if($redis->getbit($key, $uid)){   //已签到   return json_encode(['code' => 0, 'msg' => '已签到成功']);  }else{   //签到   $redis->setbit($key, $uid, 1);   $redis->setbit('checkin_'.$uid , date('z'), 1);  }

public static function getUserCheckinCount($uid){  $key =  'checkin_'.$uid;  $index = date('z');  $n = 0;  for($i = $index; $i>=0;$i--){   $bit = Yii::$app->redis->getbit($key, $i);   if($bit == 0) break;   $n++;  }  return $n; }

$key = 'checkin_' . date('ymd');$redis = Yii::$app->redis;$count = $redis->BITCOUNT($key);